Among processing for manufacturing a display or a semiconductor, ashing, etching, depositing, cleaning, nitriding processes, or the like, are performed in a low-pressure process chamber. As gas used in the low-pressure process, there are (1) volatile organic compound (trichloroethylene, 1,1,1-trichloroethane, methanol, acetaldehyde, or the like), (2) acids (HNO3, H2SO4, HCl, F2, HF, Cl2, BCl3, NOx, or the like), (3) odor producing materials (NH3, H2S, or the like), (4) spontaneous combustion gas (SiH4, Si2H6, PH3, AsH3, or the like), (5) global warming producing material (perfluoro compound), or the like.
Hazardous materials, or the like, such as fine particles, HF, fluoro compound, chloride, SiO2, GeO2, metal, NOx, NH3, hydrocarbon, and perfluoro compound, are produced by the above-mentioned low-pressure process.
Among others, HF, fluoride, and chloride corrode a vacuum pump or a joint pipe (a pipe connecting a low pressure process chamber to a vacuum pump) and therefore, are hazardous materials that should be essentially treated before being discharged in the air. The fine particles, SiO2, GeO2, metal, etc., are changed into a powder type by subjecting to a cooling process while passing through the joint pipe. The powder is a factor shortening a lifespan of the vacuum pump. The discharge of the perfluoro compound in the air should be controlled by environmental regulations.
Therefore, the hazardous materials generated in the low-pressure process chamber are abated by installing a plasma reactor in front of the vacuum pump (that is, joint pipe). The plasma reactor generating the low pressure plasma installed in the front of the vacuum pump mainly uses an electrode structure in an inductive coupled plasma method and a radio frequency (RF) driving method.
The inductive coupled plasma method generates plasma by applying voltage across an electrode having a coil shape. However, since the plasma reactor is expensive, in particular, a radio frequency (RF) power supplier is very expensive, and power consumption for maintaining plasma is large, installation costs and maintenance costs are very high.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.